Seasonal migration of Columbia spotted frogs (Rana luteiventris) among complementary resources in a high mountain basin

Information on how animals partition their activities and travel among complementary resources, such as breeding or overwintering habitats, is needed for species conservation. In a mountain basin at 2500 m elevation in central Idaho, we studied the habitat use and movement patterns of 736 marked and 87 radio-tagged Columbia spotted frogs (Rana luteiventris) from 1995 to 1998. The goals of this study were to (i) identify and characterize R. luteiventris breeding, summer foraging, and overwintering habitats, (ii) describe the movement patterns of juvenile, male, and female R. luteiventris among these resources, and (iii) determine migration routes. Juvenile and adult R. luteiventris occupied a variety of widely distributed wetlands from late June to September. On average, 1-32% of juvenile, 6-11% of male, and 16-51% of female frogs moved from breeding ponds to summer habitats. Migratory males remained within 200 m of the breeding sites, whereas females traveled up to 1030 m to reach summer habitats. From late August through September, frogs migrated to deep (>3 m) lakes to overwinter. Frog migrations occurred quickly and often followed shortest-distance travel routes through dry, open forest even when stream corridors were available nearby. This study exemplifies the need to protect both complementary resources and the corridors connecting these anuran habitats.